ESRD is a major cause of morbidity and mortality in the United States. According to the United States Renal Data System there has been a marked increase both in the prevalence and incidence of ESRD over the past decade especially in African-American patients. The objectives of this protocol are 1) to determine whether treatment of hypertension will prevent deterioration of renal function in patients with hypertensive nephropathy, 2) to determine whether the choice of antihypertensive agent affects the rate of progression of hypertensive renal disease, 3) if the course of hypertensive renal disease in the Black hypertensive can be altered by the use of more affordable antihypertensive therapy and 4) if the increased prevalence of progressive renal disease in the African-American hypertensive is related to a significant prevalence of non-hypertensive underlying renal disease. Recruitment for the full-scale trial began in March, 1995.